1. Field of the Invention
The present invention relates to a battery apparatus, battery control apparatus, and battery module control apparatus that manage the status of an in-vehicle or power supply secondary battery (lithium storage battery), and a motor drive unit that uses the battery apparatus. More particularly, the present invention relates to a battery apparatus, battery control apparatus, and motor drive unit that are suitable for use with a daisy chain of a plurality of cell controllers for managing battery cells which constitute a storage battery, and a battery controller which manages the entire storage battery.
2. Description of the Related Art
In a hybrid vehicle or electric vehicle, an assembled battery composed of a plurality of battery cells is used for a battery apparatus. The cells of the assembled battery are divided into groups of predetermined number of cells, which are called battery modules.
A conventional battery apparatus includes a plurality of series-connected battery modules to each of which a plurality of cells are series-connected, a plurality of low-level controllers (cell controllers) which are provided for each of the plurality of battery modules to control the plurality of cells constituting a battery module, and a high-level controller (battery controller) which controls the plurality of low-level controllers (cell controllers). Data is mutually exchanged between the cell controllers and the battery controller by means of serial communication.
There are various known battery apparatuses (disclosed, for instance, by JP-A-2000-74786, JP-A-2000-299939, JP-A-2003-70179, JP-A-2005-318750, and JP-A-2005-318751) that include a plurality of cell controllers and a battery controller, which are circularly connected (daisy-chained together) to establish serial communication.